Papers published
Full-Field Deformation Measurements in Liquid-like-Solid Granular Microgel Using Digital Image Correlation
McGhee, A., Bennett, A., Ifju, P. et al. Exp Mech (2017). https://doi.org/10.1007/s11340-017-0337-4
Shear history measurements due to needle dragging through a yield stress material
** experiments in progress **
Path dependence on previously printed material
** experiments in progress **
Full-Field Deformation Measurements in Liquid-like-Solid Granular Microgel Using Digital Image Correlation
McGhee, A., Bennett, A., Ifju, P. et al. Exp Mech (2017). https://doi.org/10.1007/s11340-017-0337-4
Shear history measurements due to needle dragging through a yield stress material
** experiments in progress **
Path dependence on previously printed material
** experiments in progress **
Method of deformation measurements
3D printing in yield stress materials are a recent advancement in the field of printing biological materials. The characterization of the yield stress material deformation due to a needle dragging through is important in the advancement of the manufacturing process. By showing how the printing space deforms due to a needle under various conditions, path planning strategies can be developed which account for past and future deformation to result in a more accurate finished part.
Path dependence
The major challenge in soft matter engineering is the precision in printing 3-D soft intricate constructs, so my project aimed to analyze and quantify injection needle interaction in carbomer hydrogel. Utilizing Digital Image Correlation (DIC), an optical method which allows for the measurements of displacement and strain on a full field basis, I was able to investigate a global in-plane displacement of granular gel particles to determine vital parameters that could significantly affect the manufacturing quality of three-dimensional constructs.
Shear History measurements
Shear history effects are a well known phenomenon within yield stress materials, however the way this property affects the deformation of a volume locally is not well understood. Using the deformation measurement method described above, a simple yield stress material is sheared with a needle (similar to those used in the 3D printing process) and the elastic and inelastic deformation and recovery is recorded. The goal of the experiment is to obtain some clues that help explain the physical process that causes this effect, and to use the results to aid in intelligent path planning which avoids complications that arise as a result of this phenomenon.